The present invention relates to a combination therapy for treating an HIV infection or inhibiting integrase comprising (S)-6-(3-Chloro-2-fluorobenzyl)-1-(1-hydroxymethyl-2-methylpropyl)-7-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (“Compound A”) or a pharmaceutically acceptable solvate or salt thereof in combination with at least one other anti-HIV agent. In some embodiments of the present invention, the other anti-HIV agents are chosen from reverse transcriptase inhibitors and protease inhibitors. In certain embodiments of the present invention, the other anti-HIV agents are chosen from AZT, 3TC, PMPA, efavirenz, indinavir, nelfinavir, a combination of AZT/3TC, and a combination of PMPA/3TC. Since Compound A has a high inhibitory activity specific for integrases, when used in combinations with other anti-HIV agents it can provide a combination therapy with fewer side effects for humans.